WASHINGTON (AP) -- Punctuated with the sounds of ringing phones and clinking china, President Barack Obama's new legislative diplomacy has Republicans wondering what took so long.

Obama pressed ahead Thursday with his bipartisan political outreach, eliciting a cautious welcome in a capital that has been riven by gridlock and partisanship over how to lower deficits and stabilize the nation's debt.

Obama had the Republican House Budget Committee chairman, Paul Ryan, and the committee's top Democrat, Chris Van Hollen, to lunch at the White House, a day after he dined with a dozen Republican senators in what the White House said was an effort to find common ground with rank-and-file lawmakers.

Few were willing to guarantee that the engagement would yield results. Previous presidents have tried to develop relationships with members of Congress with varying degrees of success, though some of the biggest pieces of legislation, such as the 1964 Civil Rights Act and a Social Security deal in 1983 required cross-party efforts by Presidents Lyndon Johnson and Ronald Reagan.

"We're not naive about the challenges that we still face; they exist," White House spokesman Jay Carney said. "And there are differences."

Obama has negotiated directly in the past with House Speaker John Boehner in hopes of finding a large deficit reduction deal, but those efforts have faltered as the president pursued deals with tax increases that Republicans oppose. Most recently, neither side worked hard to avoid $85 billion in automatic spending cuts and instead devolved into partisan finger-pointing over which side was more to blame.

Boehner said Obama's new approach represented a 180-degree turn. "He is going to, after being in office now over four years, he is actually going to sit down and talk to members," Boehner said. "I think it is a sign, a hopeful sign, and I'm hopeful that something will come out of it. But if the president continues to insist on tax hikes, I don't think we're going to get very far."

Carney argued that Obama's new talks with congressional Republicans did not signal a shift as much as an attempt to seize an opportunity after automatic spending cuts kicked in last Saturday but months before another fiscal deadline looms. But in briefing reporters Thursday, Carney noticeably dialed back his criticism of Republicans and emphasized the "common ground" that existed between the parties.

"The fact is, this should have been happening all along," said Sen. Bob Corker, R-Tenn., one of the dozen Republicans who joined Obama for dinner Wednesday night at a hotel a few blocks from the White House.

Sen. Lamar Alexander, R-Tenn., a veteran of Washington politics who got an ice-breaking call from Obama this week, said he appreciated his talk with Obama but said that type of engagement should have occurred much sooner.

"He's the first president in my experience, and I've known or worked with eight, who's had almost no personal relationships here in the Senate, on either side as far as I can tell," Alexander said.ms

Obama may be attempting his charm blitz later than most presidents do. Some presidents have found common ground with opponents sooner, others have not. Former Republican Senate leader Trent Lott, speaking at the 2009 ceremony unveiling his majority leader's portrait in the Senate, said he and President Bill Clinton maintained a friendly relationship even though they quarreled bitterly in public.

"Even if I did or said something stupid — or vice versa, excuse me, Mr. President — the main thing about it is that quite often we'd call one or the other and we'd laugh about it," Lott said as Clinton smiled and nodded at his side.

Senate Historian Donald Ritchie said that Reagan, during his first year in office, called every member of Congress. "His congressional liaison found that that worked against him in the long run because members of Congress expected the president to call them on every issue," Ritchie said.

Indeed, Ritchie said, no matter what the relationship is between a president and Congress, lawmakers inevitably complain that presidential outreach is not enough and presidents regularly argue that members of Congress demand too much.

Obama's outreach comes as Senate Democrats appeared to move toward easing passage for a spending measure to pay for day-to-day federal operations through September. Appropriations Chairwoman Barbara Mikulski, D-Md., said there's a "delicate balance" between supporting Obama administration priorities and going too far as to "sink the bill."

Mikulski said the Senate would give agencies including the Agriculture, Homeland Security and Justice departments their detailed, line-by-line budgets as part of legislation advancing next week to head off a government shutdown at the end of March. Other agencies would run on autopilot essentially at last year's funding levels. The automatic cuts — 5 percent to domestic agencies and 7.8 percent to the Pentagon — would apply whether or not an agency received its detailed budget.

The House passed its version of the legislation Wednesday.

Obama plans to address Republicans and Democrats in the House and Senate separately next week, the next step in his approach to spell out his agenda to lawmakers.

White House aides say the effort to reach out to rank-and-file members is designed to let the president explain his policies without the filter of party leaders, with whom he has dealt with in the past.

Along with Corker, the lawmakers in attendance at Wednesday's dinner were Sens. John McCain of Arizona, Lindsey Graham of South Carolina, Tom Coburn of Oklahoma, Kelly Ayotte of New Hampshire, Pat Toomey of Pennsylvania, Ron Johnson of Wisconsin, Saxby Chambliss of Georgia, John Hoeven of North Dakota, Dan Coats of Indiana, Richard Burr of North Carolina and Mike Johanns of Nebraska.